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SMTP problem

Discussion in 'E-mail Discussions' started by jcallery, Jan 27, 2005.

  1. jcallery

    jcallery Well-Known Member

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    We have a client who has had about 5 domains hosted with us for almost a year now. All of the sudden, last week, he could no longer send/receive mail from any of his accounts.

    He currently has a DNS line with dynamic IP.

    We added his current dynamic IP to the APF "allow" list and he could then receve email, see his sites, and receive email.


    Right now - he can do everything EXCEPT send mail. Does anyone know what could be causing this? Nobody else on the server is having the same problem. He claims that nothing has been changed in their email client settings...

    I know Brute Force and iptables are also running, though I can't imagine that they'd block just his SMTP. How could I check this? On the other hand - wouldn't he be able to get his mail as soon as his IP changed again? It changes every day...

    Any ideas?


    Thanks
     
  2. chirpy

    chirpy Well-Known Member

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    Hi John,

    Is you using POP before SMTP, or SMTP AUTH to authenticate when he sends email? Have you double-checked that he doesn't actually have his ISP's mail server configured in his client?

    Indeed, has he tried using his ISP's smtp server? That might be a better bet anyway as many ISP's these days are blocking port 25 access to other servers.

    Lastly, I'd get him to try to telnet to port 25 on your server and see if he gets the same response back as you do:

    telnet yourserver.com 25

    (quit to exit the SMTP session)
     
  3. jcallery

    jcallery Well-Known Member

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    Jonathan,
    The only problem with the telnet is that he's on Mac OSX :( Is there any similar system that we could use in mac that you know of?

    He has our smtp server typed in his settings. He was able to setup a test email account with his ISP which worked fine, but he didn't try sending mail via his domain through his ISPs server.

    Also, we don't use the authentication...

    Should I try having him type in his ISPs SMTP server into the default box?


    Thanks :)
     
  4. jcallery

    jcallery Well-Known Member

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    Jonathan,
    You're a genius, as usual :)

    I just found this on the SBC Web site - the provider that my client uses. Telcom giant SBC - the company that basically owns America's telephone system - recently blocked external access to SMTP servers.

    SBC Internet Services (SBCIS) is taking positive steps to help combat junk email and spam. In addition to network upgrades, free spam filtering and anti-virus software, SBC is implementing outbound SMTP port controls to ensure the SBC network is as reliable as possible for our Members.

    SBCIS began filtering Port 25 to separate outbound SMTP mail from dynamic IP mail. Most SBCIS Members already use SBCIS or Yahoo! SMTP mail servers for outbound email and will not be impacted by this filter.

    Members not using Web mail access or SBC mail servers, such as a private company or university mail server, will not be able to send outbound email until one of the following actions are taken:

    Convert your outgoing mail to the SBC mail servers.
    Contact your server administrator for information about alternate access methods allowing connectivity to the 3rd party mail server (i.e., VPN, Web mail or Outlook Web Access).
    Request that SBC removes the SMTP port filter from your account: on our Abuse of Service form, enter the details of your request in the Abuse Description field.
    Additional Resources & Updates
    These additional resources may be used if there is a possible issue with the SMTP port controls upgrade.



    I'll go ahead and give them a call.


    Thanks!
    John
     
  5. chirpy

    chirpy Well-Known Member

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    Well spotted. The alternative is to go to into WHM > Service Manager and enable exim to run on an additional port (the last setting) and have the user change their email client to use that port instead of port 25.
     
  6. jcallery

    jcallery Well-Known Member

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    He contacted them last night and they'll hopefully remove the filter today. I'll let you know how it goes.

    I guess they're doing this for all clients with dynamic IPs.

    If we get enough people with this problem I supposed we can try running it on another port. ...so far he's the only one.



    Thanks! :D
     
  7. spiff06

    spiff06 Well-Known Member

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    Hello all,

    I'm facing that problem just now. I'm on the road at a friend's house whose ISP is Yahoo SBC. No sending on cPanel-hosted domains is possible from Thunderbird or Outlook Express. However, I have no trouble sending via smtp.bizmail.yahoo.com.

    I've tried to run exim on a different port already (namely, 26 and 587), but to no avail. I have no idea why that doesn't work, but it just doesn't.

    Thanks for any additional pointers you can provide.
    Eric

    Edit: forgot to mention I have a dynamic IP as well.
     
  8. hexstar

    hexstar Active Member

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    Hmm, I'm running MacOS X 10.4.4 and telnet exists for me...

    Last login: Sun Jan 22 09:58:35 on ttyp1
    Welcome to Darwin!
    john-musbachs-powerbook-g4-12:~ hexstar$ telnet --help
    telnet: illegal option -- -
    Usage: telnet [-4] [-6] [-8] [-E] [-K] [-L] [-N] [-S tos] [-X atype] [-c] [-d]
    [-e char] [-k realm] [-l user] [-f/-F] [-n tracefile] [-r] [-s src_addr] [-u] [-P policy] [-y] [host-name [port]]

    You can access the terminal by going to HD>Applications>Utilities :)
     
  9. spiff06

    spiff06 Well-Known Member

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    (Uh-oh, looks like I replied to a year-old thread again...)

    So, well, one working option to keep a Yahoo ISP happy is to set your client to access... a Yahoo SMTP server. In my case, using a Business Mail account (smtp.bizmail.yahoo.com) allows me to send messages properly. It's likely going through smtp.yahoo.com with a standard Yahoo Mail ID and password will not make Yahoo SBC block outgoing mail.

    This is obviously not specifically a cPanel issue, but, who knows, I may not be the last one to wonder about this and come to this forum for answers...
     
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